Refrigerating apparatus



Spt. 17, 1935. I L. C, SMlTH 2,014,703

REFRIGERATING APARATUS Original Filed Mach23, 1952 2 Sheets-Sheet l FIG. 2

Snnentor 0a/rence C fn/5% attorney Sept. 17, 1935. c. SMITH REFRIGERATINGA AIVPARATUS 2 Sheets-Sheet 2 Original Filed March 23, 1932 FIG. 8

FIG. I0

(Ittorneg Patented Sept. 17, 1935 UNITED STATES PATENT oFFiCE I REFRIGERATING APPARATUS Lawrence C. Smith, Bulalo, N. Y., assigner to Fedders Manufacturing Company, Inc., Buffalo, N. Y.

3 Claims.

This application is a diyision of my copending application Serial No. 600,604, led March 23, 1932.

This invention relates to refrigerating appall ratus and it has particular reference to a refrigerating unit suitable for use as an evaporator, and to a method of making the same.

The present invention is directed toward the successful and economical manufacture of evaporators or like refrigerating apparatus of what isgknown as the pressed type. The manufacturers of evaporators have found that in the making of such devices with copper tubing, considerable manufacturing costs are involved in order to provide a satisfactory product, and to reduce the cost of manufacture, it has been suggested during the past few years to prepare the evaporator from two fiat sheets of metal, one or both of which was deformed, so that When the plates were mutually united, there would be provided therebetween a passage for the refrigerant.

Unfortunately, however, investigation and test of this method of making evaporators revealed 85 some unanticipated problems which could be cured only by the introduction of manufacturing steps or methods bringing the cost of the final product up to the same level as that theretofore experienced in evaporators of ordinary w tubular construction. It was found, for example, that with special grades of steel suggested as desirable because of oxidation resistant properties, tremendous pressures were required to drawthe metal, and it was also found that subsequent Welding operations caused the metal to scale and thereby be less suited for its intended purpose. When recourse was had to brass or copper as a material of construction, it was found that special grades of these materials il@ were required to produce a satisfactory product, and this entailed an appreciable cost of raw materials.

According to the present invention, there is M provided a simple and eiective method for making an evaporator or similar refrigerating unit, which unit is of itself of novel and useful construction. This evaporator is devised to provide continuous inner and outer walls formed my from metal of high heat conductivity, suchas copper or brass, and of relatively light Weight, and, after deforming one or both of the metal plates with a channel or elongated depression, there is inserted prior to nal assembly acopper tubing which is subsequently formed and held between the plates to provide an ,encased conduit for the refrigerant.

In a device of this character, recourse to expensive die-forming machinery is not required, nor need any apprehension be had because of 5 the possibility of scaling or flashing of the metal during the welding operations by means of which the plates are mutually secured. The resulting structure, therefore, may be made with a minimum of effort and cost, and, by virtue of its l0 continuous wall construction, is highly eiective as a heat radiating or absorbing apparatus.

The following description and drawings illustrate several exemplary adaptations of the invention, wherein:- l5

Fig. 1 is a perspective view of the inner plate, coil and outer plate in their proper relative arrangement preparatory to the forming and securing operations.

Fig. 2 is a side elevation of the superimposed 20 members diagramatically showing their position in a die prior to the coil flattening operation.

Fig. 3 is a side elevation of the members diagrammatically showing the pressure securing operation. Fig. 4 is a front elevation of an assembled unit prior to the finishing operation and formed to provide an evaporator device.

Fig. 5 is a perspective view of a finished evaporator device.

Fig. 6 is an enlarged cross section through one edge of the plate assembly of Fig. 2, showing the relative proportions between the formed depression and the coil.

Fig. 7 is an enlarged fragmentary cross section 35 through one edge of the assembled and formed device as shown in Fig. 3,

Fig. 8 is an elevation of a further embodiment of the invention, portions of which are broken away to show the ice tray shelf arrangement. d0 v Fig. 9 is a section on the line @-t of Fig. 8.-

Fig. 10 is a perspective 'view of the ice tray shelf in inverted position.

Fig. 11 is an enlarged section on the line ll--ll of Fig. 8, to which is' added a cross sec- 45 tional illustration of a preferred form of connection fitting.

In the drawings, Figs. 1 to 4 diagrammatically illustrate, in their relative order, the operations performed in constructing the embodiment of the evaporator device 20 shown in Fig. 5. This evaporator is a laminated structure formed of three parts (Fig. l), an'inner plate 2l which is preformed with two series of shelf guide projections 22, and a pair of shelf stop projections it, t5

and outer plate 24, which is somewhat narrower than the plate 2|, and containing a serpentine depression 25, the ends of which terminate in formed bosses 26; and finally a tubular coil 21 formed with a plurality of convolutions 28 adapted to be received in the .depression of the plate 24, and having laterally extending end portions 29 adapted to project through the bosses 26 of the plate 24.

The above described preformed members are inserted in a die, the plate 24 being the first inserted and mounted on a stationary die block 30 having female portions adapted to conform to the relief of this plate, following which, the coil 21 is placed in the depression of the plate 24 and is covered by the plate 2|, which is mounted thereon in longitudinal mismatched relation to the plate 24 for reasons hereinafter more fully set forth. Attention is directed to Fig. 6 which more clearly shows the relative arrangement of the superimposed members, wherein the relatively shallow depression 25 receives the coil 21 which projects above the surface of the plate 24 and spaces the plate 2| from the same. Subsequent to this loose assembly, the upper die 3| is actuated to press the plate 2| to the surface of the plate 24 and to concurrently flatten the coil 21 therebetween, which will thereby be formed to the enclosing contour of the two plates as shown in Fig. '7. The same die is devised to simultaneously roll the overlapping longitudinal edges of the plate 2| into contact with the plate 24, as indicated at 32, thus securing the members against disassembly when removed.

The next operation consists in securing the plate 2| to the plate 24 at points between the edges of the same, and is preferably accomplished in a welding device of the well known pressure type, wherein the plane or surface portions of the plates, which at this time are in slightly spaced relation due to the slight expansion of the coil 21 after the flattening operation, are again brought in intimate contact through the clamping action of the welding device 35 and are secured by welding in such position (Fig. 3).

The plates and coil thus formed and assembled in a unit are bent into shape to form any desired shape of evaporator, wherein the mismatched ends 36 are lap-welded to form a rough annulus or cylinder adapted to receive an ice tray on its oppositely located projections 22. (Fig. 5.)

It is preferred that the coil 21 have a thicker wall section than the plates 2| and 24 (Fig. rI) since this has been found not only to facilitate the forming of the plates but to increase the thermal efficiency of the device, as it will be obvious that the plates in effect forni a continuous absorption fin for the coil 21.

The second embodiment of the invention (Figs. 8 to 11) comprehends the provision of an evaporator similar to that of the first embodiment, but altered in the respect that it is adapted to house and cooperate with a refrigerant carrying shell 36. This evaporator 4| is provided with inner and outer shells or plates 42 and 43 and a coil 44 mounted therebetween which is received in the serpentine depressions 39 and 40 formed in plate 43. This coil is similar to the described coil 21, with the exception that it is broken to provide a series connection to the shelf 38. The coil is thus formed of two sections, the shorter of which, the section 45, is mounted in the depression 39 and provided with a lateral end portion 46 projecting through a suitable opening in the inner plate 42 and with a second end portion 41 projecting through a boss 48 formed in the outer plate 43. Similarly, the remaining section 49 is mounted in the depression and is provided with an end 50, extending through the inner plate, and an end 5| extending through the boss 52 at the remaining end of the serpentine depression 40.

The inner plate 42 is provided with opposed series of projections or lugs 53, serving as a sup- 14 port for the shelf 38. (Fig. 9.) The shelf comprises -a fiat upper plate 54 and a lower plate 55 which is formed with a serpentine-depression 56 for receiving a tube coil 51. These members are secured together by bending the edge of the plate 1l 54 over the margin of the lower plate 55, as indicated by the numeral 58, and also by welding the plates at contacting points at spaced intervals. The ends 59 and 6| of the coil 51 are bent lat- `erally and project through openings 62 in the 21 extremities of the depression 56 for connection with the ends and 46 respectively of the evaporator coil 44 by means of suitable fittings 63.

The evaporator input and output ends 41 and 5| are connected to the condenser and pump re- 2 spectively by means of fittings of the type illustrated in Fig. l1, wherein the boss 52 is internally threaded to receive a nipple 64, which is drilled to engage over the coil end 5|, and is counterbored at 6,5 to receive a portion of solder which 3 locks the same to the tube. This member is also provided with a second threaded portion 66 for entering a clamping fitting 61 which is screwed down to contact the solder and thus seal the tube end 5| against liquid or gas escape. The fitting 3 61 is suitably formed at its upper extremity to provide a mounting means for a connecting tube 68 through which the products of evaporation are returned to their source.

It is not intended that the method described be 4, limited in its use to the specific devices illustrated, as it will be obvious that the principle of construction may be utilized for numerous allied products without departing from the spirit of the invention.

I-claim: 4

1. A refrigerating device comprising a metallic sheet having a serpentine depressed portion formed therein, a second sheet vsecured to the first sheet and covering said depressed portion, and a tube coil in said depressed portion con- 5 forming thereto and resiliently engaged by both of said sheets.

2. A refrigerating device comprising a metallic sheet having a serpentine depressed portion formed therein, said portion having an opening 5 at each extremity, a second sheet secured to the first sheet and covering said depressed portion, and a tube coil in said depressed portion conforming thereto and resiliently engaging both of said sheets, said tube coil having end portions extend- 6 ing through the openings of said depressed portion.

3. A refrigerating device comprising a metallic sheet having a .serpentine depressed portion formed therein, said depressed portion being sub- 6 stantially semi-circular in cross section, a second sheet secured to the first sheet and covering said depressed portion, and a tube mounted in said depressed portion and engaging said second sheet, said tube being formed to conform to the cross 7 sectional shape of said depressed portion.

LAWRENCE C. SMITH. 

